Drill



July 19, 1932. H. c. NORLEY 1,867,950

DRILL Filed Nov. 13. 1951 //Vl /V7"0R H. c. NORLEY Patented July 19, 1932 UNITED STATES PATENT OFFICE HARRY CHARLES NORLEY, 0] NORTH BAY, ONTARIO, CANADA, ASSIGNOB T0 CAQNAIDIAN ATLAS STEELE LIMITED, OF WELLAND, ONTARIO, CANADA, A CORPORATION OF CAN ADA DRILL Application filed November 13, 1931. serial No. 574,850.

My invention relates to improvements in drills, and the object of the invention is to devise a connection between the steel shank and bit particularly adaptable for use when the drill shank is operating horizontally such as in rock mining, quarrying and tunneling and which will simplify and cheapenthe manufacture by avoiding threading and other expensive operations, and it consists essentially of the arrangement and construction of parts as hereinafter more particularly explained.

Fig. 1 is a perspective view of a portlon of a drill shank and bit and showing my connector applied thereto. I

Fig. 2 is a plan sectional view taken on line 2-2 Fig. 3.

Fig. 3 is a sectional view on line 3-3 Fig. 4 is a sectional view on line 44 Fig 2.

igs. 5, 6 and 7 are perspective details of the shank, connector and bit separated apart.

In the drawing like letters of reference indicate corresponding parts in each figure.

1 indicates the lower portion of a shank which may be octagonal in section as shown or cylindrical or any other form desired. The lower end of the shank is provided with a cylindrical tapered portion 2. 3 is a bit provided with a recess 3* in its upper face in which the lower end of the table portion 2 of the drill shank fits.

Between the cutting portions 3 of the bit and wall of the recess 3* is cut away to form notches 4 which notches are preferably placed diametrically opposite and from which extend in opposite directions internal cam grooves 4* and 4, the groove inclining downward slightly as indicated by dotted lines in Fig. 4 and into which diametrically opposite projections 5 and 5* extend when the parts are connected together. When making such connection the tapered portion 2 of the shank is fitted into the recess 3*, the projections 5 and 5* passing into the notches 4. When in this position the shank and bit are rotated relatively in opposite directions so that the projections 5 and 5* pass into the internal cam grooves 4* and 4 engaging the downwardly inclined upper wall thereof so as to draw or cam up the bit so that the portion 2 of the steel bit fits tight in the recess 3* leaving a clearance when the shank first enters the bit 1 of an inch which is taken up by the impact.

In operation the bit rotates in a counter clockwise direction and, therefore, as such operation takes place there is a tendency for the bit to increase in tightness as the drive is carried from the shank to the projections 5 and 5* thereof to the Walls of the recesses 4* and 4 of the bit. In order to lock the parts in the above position I provide a split spring ring 6 which surrounds the portion 2 of the steel shank and is provided with downward projections 6* and 6 which fit into the notches 4 and thereby close the open ends of the slots 4* and 4 so that when the rotation of the bit is reversed prior to withdrawal the 'parts will not disengage. When the bit is withdrawn all it is necessary to do is to draw the spring ring 6 upward upon the portion 2 of the shank so asto carry the projections 6* and 6 out of the notches 4 permitting the projections 5 and 5* passing from the grooves 4* and 4 into such notches so that the bit may bewithdrawn longitudinally from the end of the shank.

From this description it will be seen that I have devised a very simple device for connecting a drill bit to a shank which is par- I ticularly adaptable for use when the bit and shank are revolving horizontally, which will enable the bit being easily removed from the shank when withdrawn from the bore to be replaced or renewed whenever desired and which will eliminate the threading of the bit upon the shank and locking the bit on the thread, which has been found in practice to be not only expensive and costly to manufacture but also not altogether practical in operation.

What I claim as my invention is:

1. The combination with a drill shank having a cylindrical end, of a drill bit provided with a recess into which the end of the drill shank fits, means for engaging the bit and shank together by rotary movement, and a and means carried by the ring for preventing disen ment of the bit.

2. e'combination with a drill shank having a c lindrical end of a bit havin a recess 5 into w oh the end fits and aving a notched wall, means engagin the bit and the shank together operated by t e relative rotation thereof, and a split spring ring mounted upon the cylindrical portion of the shank 10 and engaging the notched portion of the bit to prevent disengagement of the'parts.

3. The combination with a drill shank having a cylindrical end, of a bit having a recess into which the shank end fits, said recess having a notched wall and a circumferential internal groove extending from said notch portion, a projection extending from the cylindrical portion of the shank adapted to fit into the notch portion of the bit, and to pass by circumferentialmovement between the bit and shankinto the internal groove thereof, a spring split ring mounted upon the cylindrical portion of the shank and rovided with a projection fitting the notch o the bit.

35 4. The combination with a-drill shank, of a bit having a recess into which the shank end turnably fits, a projection and coactin bayonet slot connection between the sha v and bit, and a withdrawable stop in the slot for preventing disengagement of said projection and slot.

HARRY CHARLES NORLEY. 

